OSG Screw Thread Insert STI Tap: Spiral Fute, 3/4"-16 UNF, H3 / 2B-3B, 4 Flute

An OSG spiral-flute STI tap is used to cut internal threads for screw thread inserts in materials that produce stringy chips, such as aluminum and low-carbon steel. The spiral flute design evacuates chips upward, preventing clogging in blind holes. It is commonly applied in aerospace, automotive, and general manufacturing where reliable thread repair or reinforcement is needed.

The OSG 10801800 is a spiral-flute STI tap with a 3/4"-16 UNF thread size, H3 / 2B-3B tolerance, 4 flutes, and a bottoming chamfer. It is designed for screw thread insert installation. The H3 ground thread limit ensures precise fit for class 2B or 3B internal threads. This tap is made by OSG, a leading cutting tool manufacturer.

You can source OSG STI taps worldwide through 3G Electric, a global industrial equipment distributor established in 1990. We handle full logistics, customs clearance, and delivery to your location. Contact us for availability and lead time. We supply genuine OSG cutting tools to manufacturing facilities across multiple industries.

To select the correct STI tap, match the tap thread size and pitch to the insert's nominal thread (e.g., 3/4"-16 UNF). Use a bottoming chamfer for blind holes or a plug chamfer for through holes. Choose spiral flute for chip evacuation in ductile materials. Verify the tap tolerance (e.g., H3) aligns with the required thread class (2B or 3B). OSG taps are a reliable choice.